145051 20240926122721.0 doi 10.1016/j.apsusc.2024.161180 sideral 139918 ART-2025-139918 eng Cabaço, João S. Modifying vacancy defects during systematic disordering of the Cr2AlC nano-lamellar system 2025 The layered structure of MAX phases is associated with a number of functional properties and is the subject of extensive research. While the unit-cell layers of these structures have been well studied, much less is known about the distribution and manipulation of point defects within them. Here, we selected the prototype Cr2AlC system and, using variable energy positron beams, observed Doppler broadening and positron annihilation lifetimes to track the evolution of defects caused by the penetration of energetic transition metal ions (Co+ and Mn+) and noble gas ions (Ar+ and Ne+). In all cases an overall reduction of the open-volume defect concentration is observed post-irradiation. Atomic displacements induced by the penetrating ions drastically modify the defect distribution: the concentration of agglomerates of 9–15 vacancies (corresponding to positron lifetimes of 335–450 ps) in the precursor [Cr2C/Al]n layers is suppressed, whereas Al mono- and Al-Cr di-vacancy (lifetimes 217–231 ps) concentrations are enhanced. This breakdown of large defects into point defects scales with atomic displacements and is largely independent of the penetrating ion species, providing insights into the manipulation of point defects in nano-layered systems. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/DGA/E13-23R info:eu-repo/grantAgreement/ES/DGA-FEDER E28-23R info:eu-repo/grantAgreement/EC/H2020/823717/EU/Enabling Science and Technology through European Electron Microscopy/ESTEEM3 This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 823717-ESTEEM3 info:eu-repo/semantics/openAccess by-nc http://creativecommons.org/licenses/by-nc/3.0/es/ info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Liedke, Maciej Oskar Pablo-Navarro, Javier (orcid)0000-0001-6771-6941 Ganss, Fabian Magén, César (orcid)0000-0002-6761-6171 Ibarra García, Manuel Universidad de Zaragoza (orcid)0000-0003-0681-8260 Kentsch, Ulrich Butterling, Maik Wagner, Andreas Lindner, Jürgen Faßbender, Jürgen Leyens, Christoph Boucher, Richard Bali, Rantej 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 679 (2025), 161180 [10 pp.] Appl. surf. sci. Applied Surface Science 0169-4332 6124481 http://zaguan.unizar.es/record/145051/files/texto_completo.pdf Versión publicada 2509478 http://zaguan.unizar.es/record/145051/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:145051 articulos driver 2024-09-26-10:58:28 ARTICLE